<template>
  <div class="app_container">
    <!-- 顶部 Header 区域 -->
    <!-- 固定定位，不占标准流 -->
    <mt-header fixed title="固定在顶部Vue项目">
      <span slot="left" @click="goBack">
        <mt-button icon="back" v-show="flag">返回</mt-button>
      </span>
    </mt-header>

    <!-- 中间的路由  router-view 区域 -->
    <transition>
      <router-view></router-view>
    </transition>

    <!-- 底部 Tabbar  区域 -->

    <nav class="mui-bar mui-bar-tab">
      <router-link class="mui-tab-item1" to="/home">
        <span class="mui-icon mui-icon-home"></span>
        <span class="mui-tab-label">首页</span>
      </router-link>
      <router-link class="mui-tab-item1" to="/member">
        <span class="mui-icon mui-icon-contact"></span>
        <span class="mui-tab-label">会员</span>
      </router-link>
      <router-link class="mui-tab-item1" to="/shopcar">
        <span class="mui-icon mui-icon-extra mui-icon-extra-cart">
          <span class="mui-badge" id="badge">{{ this.$store.getters.getAllCount }}</span>
        </span>
        <span class="mui-tab-label">购物车</span>
      </router-link>
      <router-link class="mui-tab-item1" to="/search">
        <span class="mui-icon mui-icon-search"></span>
        <span class="mui-tab-label">搜索</span>
      </router-link>
    </nav>
  </div>
</template>
    
<script>
export default {
  data() {
    return {
      flag: false, //控制是否显示后退按钮
    };
  },
  methods: {
    goBack() {
      //点击后退
      this.$router.go(-1);
    },
  },
  created() {
    if (this.$route.path === "/home") {
      this.flag = false;
    } else {
      this.flag = true;
    }
  },
  watch: {
    //监听url， 在home的时候，隐藏后退按钮
    "$route.path": function (newUrl) {
      if (newUrl === "/home") {
        this.flag = false;
      } else {
        this.flag = true;
      }
    },
  },
};
</script>

<style scoped lang="scss">
.app_container {
  padding-top: 40px;
  padding-bottom: 50px;
  // 动画时，底部有滚动条，所以，让container外面，即右侧部分不可见
  overflow: hidden;
}
.v-enter {
  opacity: 0;
  transform: translateX(100%);
  // 动画时，不让下来再上去
  // position: absolute;
}
.v-leave-to {
  opacity: 0;
  transform: translateX(-100%);
  position: absolute;
}

.v-enter-active,
.v-leave-active {
  transition: all 0.5s ease;
}

// 改类名，解决tabba点击不能切换的问题。原因是样式有冲突，导致不能切换
// 把.mui-tab-item改为了.mui-tab-item1，并在本组件中加以应用
.mui-bar-tab .mui-tab-item1.mui-active {
  color: #007aff;
}
.mui-bar-tab .mui-tab-item1 {
  display: table-cell;
  overflow: hidden;
  width: 1%;
  height: 50px;
  text-align: center;
  vertical-align: middle;
  white-space: nowrap;
  text-overflow: ellipsis;
  color: #929292;
}
.mui-bar-tab .mui-tab-item1 .mui-icon {
  top: 3px;
  width: 24px;
  height: 24px;
  padding-top: 0;
  padding-bottom: 0;
}
.mint-header {
  z-index: 99;
}
</style>